Copyright 2006 John Wiley & Sons, Inc Chapter 9 – Task In The Organizational Context HCI:...

Copyright 2006 John Wiley & Sons, Inc

Chapter 9 – Task In The Organizational Context

HCI: Developing Effective Organizational Information Systems

Dov Te’eniJane CareyPing Zhang


Learning Objectives

Know the attributes of the organizational tasks pertinent to HCI and how they provide the context of tool-level task.

Understand the need for task analysis in HCI. Understand how the work context affects HCI design

and differentiates between structured and non-structured tasks.

Understand how organizational-level tasks are decomposed hierarchically and mapped to tool-level task, which are described by the TSSL model.

Understand and apply a method for analyzing the HCI requirements for decision support.


Project Selection Project Planning

Requirements User-Needs TestDetermination

Context User TaskAnalysis Analysis Analysis

Evaluation FormativeMetrics Evaluation

Alternative Selection

Interface SpecificationFormativeEvaluation

Metaphor Design Media Design Dialogue Design Presentation Design

Coding Formative Summative

Evaluation Evaluation

Human Concerns:PhysicalCognitiveAffectiveUsefulness

Implementation

Project Selection and Planning

Analysis

Design

HC

I Prin

ciple

s an

d G

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es

Re

qu

irem

en

tsDe

term

ina

tio

n

User Needs Test

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textA

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Introduction

Dowell and Long (1989) regard the workers and the information systems as “work systems” that affect some domain (e.g. customer services) through work aimed at achieving organizational goals by means of a set of tasks.

Eventually, task analysis; determines how task achieves the work must dictate not only which tasks achieve work but

also how they are allocated to the computer and the user.


Introduction

Topics covered include task, work and their relation to HCI that begins with; Examining the task, at both the

organizational level and the tool level, Concentrates on characteristics of

organizational tasks and finally, Examining the impact of work on user

requirements.


Introduction

The HCI developer needs to understand; How the work is structured and performed in order

to understand how workers divide and coordinate their work into specific tasks.

The dynamics of work patterns to recognize opportunities to support work over time.

The workplace, with its computers and other artefacts, does not always behave as expected.

People behave in unpredicted and unplanned ways.


Introduction

Task is central to HCI. The TSSL model describes HCI by representing the user’s view of the task and its human-computer implementation.

The organizational context affects HCI in two ways; Characteristics of the organizational tasks and

the workplace affect user behavior and user requirements

Specific organizational tasks map onto specific tool-level tasks.


2.0 Characteristics of Organizational Tasks

Selecting an office

View two sites

Select two sitesto view

Define viewattributes

• Computer displays list of sites, and user selects two sites• Each site is identified by name and picture. Users can select or deselect a site.• User points at a name or picture and then selects an unselected or deselects a selected. Sites are ordered by name.• Sites are displayed in a checkbox list and users point or tab to a checkbox and either click or press any key on the keyboard.

Figure 9.3 Hierarchical task decomposition, with both the organizational-level tasks and thetool-level task described by the TSSL levels of how to operate the computer.

Org

an

izatio

na

lL

ev

el ta

sk

To

ol

Le

ve

lta

sk

No

te : B

roke

n lin

es

ind

icate

Inco

mp

lete

de

scriptio

ns

TSSL


2.0 Characteristics Of Organizational Level Task Organizational-Level Task :-

A worker’s designed (intended and planned) effort to accomplish an organizational demand.

Structured Task :- Task that is well defined, has clear and explicit

goals, and can be accomplished by following predefined procedures.

Non-structured Task :- Task that is ill-defined, has ambiguous goals (if it

has any at all), and has no explicit procedures that can ensure successful completion of the task.


Table 9.1 summarizes the impact of task characteristics on the focus of HCI design. It emphasizes the differences in the impact of different types of task on the users and their performance because different types of task require different resources. The different impacts, in turn, determine the corresponding type of support.

2.0 Characteristics Of Organizational Level Task


Table 9.1 The importance of Task Structure to HCI

Typ

e and

Co

ntext o

f T

ask

Exa

mp

le

Main

Imp

lication

s

Structured, routine, uniform

, repetitive ta

sks

Intensive data

entry

Minim

al user e

ffort and ma

ximum

speed; m

inimal learn

ing time; errors due to inatte

ntion a

nd boredom

; frustration w

ith ill-fitted interfaces (e.g. no shortcuts); physiological

stress

Structured to sem

i-structured, routine but d

iverse

tasks

Word processing

Minim

al user e

ffort and ma

ximum

speed fo

r certain op

erations; piecem

eal b

ut efficient learning; recall and skill n

ecessary to operate; errors due to misapplication

of rules; fit to specific tasks an

d to specific work habits; lim

ited problem

solving and

calculations

Unstru

ctured tasks

Sup

ported decision ma

king

Com

prehension

; creativity and flexibility; complex problem

solving and planning; sim

ulations, calculatio

ns’ and m

ental models; e

rrors and biases in ju

dgments; fit to individual

style

Multiple ta

sks concu

rrent

Ope

rating seve

ral office systems

Managin

g attention to se

veral task; controlling states and opera

tions in several system

s; confusion and overload leading to errors and

frustration

Interrelated tasks

Project m

anagement

Com

prehension

; comp

lex problem

solving; m

emory; sim

ulation and plann

ing; flexibility


3.0 Work At The Office As Context – Tasks and their interrelations

Transaction Processing System (TPS) Organizational Processing System (OIS) Management Information System (MIS) Decision Support System (DSS)

3.1 C

haracteristics O

f D

ifferent T

ypes Of

Work

The

variety of tasks found in organizations is very large and best reflected in the various types of com

puter system

i.e.,

The

variety of tasks and of users is the basis for exam

ining the im

plications on the type of required computer support


3.1 Characteristics Of Different Types Of Work

Often very unstructured. Involves many interrelated tasks. Managerial work probably the most complex

that combines most types of tasks (Table 9.2).

Professional

Work :-


Table 9.2 Propositions about Managerial Work (Adapted from Kurke & Aldrich, 1983)

Managers perform a great quantity of work with little free time (34 different activities per day, 44 hours a week).

Managerial jobs are characterized by brevity, variety, and fragmentation (63 % of activities lasted less than 9 minutes; only 5 % lasted more than an hour).

Managers favor verbal over written contacts (desk work and tours take up only 29 % of their time and the rest is for phone calls and meetings).

Scheduled meetings consume more time than any other activity (4 meetings a day with half involving 3 people or less).

Managers link their organization with outsiders in a variety of ways (external contacts took 52 % of verbal contacts; internal contacts over a third).


With reference to Table 9.1, the description of work environment highlights the aspects of human information processing that are more likely to suffer from the limitations and biases mentioned previously; The typical manager is likely to suffer from information

overload. To function effectively (as monitor, disseminator,

spokesperson) information must flow to and from the manager quickly.

The cognitive limitations on memory and processing become a critical threshold.

Support is needed to: Reduce the amount and complexity of information

processing Increasing the capability of memory, processing,

attention and comprehension.

3.2 Information Processing Functions Supported By HCI


Table 9.1 The importance of Task Structure to HCI

Ch

aracteristics of M

anag

erial Wo

rk

Ch

aracteristics of C

lerical S

up

po

rt W

ork

User L

imitatio

ns

Informa

tion o

verload

Informa

tion o

verload

Mem

ory, atte

ntion, cognitive

processing

Concurrent tasks

overload

Concurrent task overloa

d

Cognitive m

anagem

ent

Com

plex problem

solving

Mem

ory, cognitive

processing

Use

of mu

ltiple m

edia for

comm

unica

tion

Percep

tual p

rocessing


3.3 Work ModelingT

he application of the ideas m

entioned earlier (the types of tasks, the interrelations am

ong tasks, and the w

ork habits of the w

orkers who

perform the

tasks) in a particular w

ork setting for a particular com

puter system

(or system

s) m

ay require a special analysis.

One approach that begins the developm

ent of IS by

lookingat the w

ork context is the “Contextual D

esign” (Beyer &

Holtzblatt, 1998).


1. Contextual inquiry2. Work modeling3. Consolidation4. Work design5. User environment design6. Test with customers7. Putting into practice

3.3 Work Modeling

Contextual has seven

parts :-

NO

TE

:-T

he first 3 p

arts areth

e main

con

cern

of

this ch

apter


3.3 Work Modeling

1. Contextual inquiry : Determines the stakeholders and attempts to

model how they work in practice. Using a variety of interview techniques, contextual inquiry represents the users’ work habits, motivation, needs, and desires.


3.3 Work Modeling

2. Work modeling : Represents the tasks performed by individual workers and

interacting workers. Modeling techniques resemble objects orientation tools and diagrams. One diagram represents the allocation of tasks to workers and another represents the interrelations between tasks. Additionally, each task is described individually (like a flowchart). Moreover, modeling also includes the interactions between workers, both the formal interactions around tasks and the informal interactions.

Work modeling goes further, however, by looking closely at the physical environment. It seeks to identify how workers use physical artifacts such as notes and desks to manage their work. (E.g. how a worker arranges his desk may indicate certain needs that would have to be satisfied in a paperless office.


3.3 Work Modeling

3. Consolidation : This is needed when (assumed in contextual

design) the design is done in teams. It combines the information gained from individual interviews to form a holistic view of work.


4.0 Decision Making As Organizational Task

4.1 T

he

Dec

ision

L

ife-C

ycle as a B

asis fo

r D

etermin

ing

R

equ

irem

ents

Helps to identify the opportunities for supporting the user (Te’eni, 1992).

Should not be confused with the HCI Development Life Cycle, which describes how to develop a computerized system.

Defines the main activities involved in a decision-making process and how they progress from one activity to another.

The life cycle can then be used to determine what resources are needed for each activity. what the user’s limitations and strengths are in performing the

activity what functionalities are needed to overcome the limitations and

extend the strengths. 5 main stages of the decision life cycle are shown in Figure 9.4.


Figure 9.4 Decision Life-CyclePre-decisional

activitiesInform

ation acquisition

Structuring and clarifying

information E

valuation of alternatives and choice

Post-decisional

activities


4.1 Decision Life-Cycle

1. Pre-decisional Activities : Include complex processes such as problem

detection, strategy formulation, and strategy selection.

2. Information Acquisition : Includes all forms of obtaining information

from external sources as well as retrieving information from one’s own memory.



3. Structuring and Clarifying Information : Involves complex processes aimed at making

sense of the decision situation and the available information so as to be able to make a decision.

4. Evaluation of Alternatives and Choice : Is the most obvious part of decision making. Involves comparisons of alternatives with

some structure defined in the previous stage.



5. Post-decisional Activities : Is often valuable to examine the activities after

the choice is made in order to identify further opportunities of supporting the user.

It is important to consider the affective aspects that follow from a decision i.e., the user’s confidence in and conformance with the decision made.

Learning from feedback about the decision and revising accordingly all or part of the earlier stages in the Decision Life Cycle.


1. Availability (Tversky & Kahneman, 1974). People tend to use information that readily available to them and ignore information that is less available, even if it is from reliable sources.

2. Confirming information ((Hogarth, 1987). People tend to seek and accept information that confirms rather than disconfirms their expectations.

3. Selective perceptions (Hogarth, 1987). The bias toward confirming information is the form of selective perception.

4.1 Decision Life-CycleInformation acquisition, both from

external and internal (m

emo

ry) sources, is subject to several biases. C

onsider the follow

ing 3 biases;


4.1 Decision Life-CycleT

he lim

itations and biases discussed in relation to each of the 5 stages in the D

ecision Life C

ycle im

ply several types of support for users engaged in decision m

aking. An

attempt to

organize the needs for supporting decision m

aking is show

n in T

able 9.4.


1. Working with the system, appropriate functionality can reduce the user’s effort in each step of the Decision Life Cycle (Figure 9.4).

2. It can reduce errors (e.g. in computation).3. It can affect the user’s selection of decision

strategy by making one strategy more attractive to the user than other strategies (Te’eni, 1989; Todd & Benbasat, 1992).


How

system’s functionality affects user behavior;


Table 9.4 Common Needs of Decision Making (Silver, 1991)

Fuller exploration of alternatives. Earlier detection of problems. Coping with multiple objectives. Treat risk. Reduce cognitive biases. Creativity Communication Structure decision-making process Learning


4.2 Levels of Interaction in Decision Making (Figure 9.5)

An

exampl

e

of

the

appl

icat

ion

of

the

Hierarchi

cal

Task Decomposition.

Find the best location for a new

shop

List possible options

Predict no. ofcustom

ers

Estim

ate costs

View

the sites

Com

puter displaysall options for newshop

- Com

puter presentscustom

ers forecaststem

plate- U

ser inputsparam

eters- C

omputer

calculates anddisplays forecasts

- Com

puterpresents costtem

plate- U

ser inputsparam

eters- C

omputer

calculates anddisplays costs

- Com

puter displayslists of sites- U

ser selects one- C

omputer displays

the site- U

sers view it

To

ol

level

Decisio

n

level


1. Use of internal representations.2. Pursuit of goals.3. Chunking of information.

5.0 A Method For Task Analysis And Decision Support

5.1 An Overview

of the Method

Wane

Zachary

(1998) w

as one of the first to integrate design tools for D

SS

based on cognitive engineering. H

is m

ethodology assum

ed that hum

an decision m

aking depends on;


1. Working memory.2. Cognitive processing.3. Retrieval from long-term memory.4. Numerical operations.5. Projection in time and space.


5.1 An Overview

of the Method

Furt

herm

ore, human decision m

aking is lim

ited by 5 factors:



5.1 An Overview

of the Method

- Figure 9.7

describes a process of designing a D

SS

that is adapted from

Z

achary’s m

ethodology. It begins w

ith an analysis of the task and its constraints, continues w

ith a specification of the functionality required, and then proceeds to a design of the technology

- Z

achary’s m

ethodology assum

es that characteristics of decision m

aking lead to several recurring problem

s, w

hich can be m

inimized

by a system

atic process of analysis and design.



Fi

gure 9.7 Analysis and Design of DSS

1. Situational and Functional Analysis (organizational context, work style, task attributes, objective and perceived

effectiveness, task dynamics, decision process, data and knowledge resources, problem representation, required judgments, errors)

2. Constraint Analysis (human limitations and biases, data constraints, communication failures,

stress)3. Propose New Functionality

(redefine elements of the decision process and the allocation of task to human and computer)

4. Design HCI, Models, Data, and Control (design detailed human-computer interfaces, computerized decision

techniques, data management, and control over the system operation throughout the human-computer interaction; develop prototype)

5. Reanalyze Work with New DSS and Modify (for objective and perceived effectiveness and for new constraints)



The essence of this stage is to define the decision problem and decompose its goal into sub-goals.

Its main tool is a protocol for collecting and analyzing information

Its product is a Summary Tabulation of Aiding Requirements STAR Table (Figure 9.8)

The goal decomposition should; concentrate on concrete goals work top-down from the more general to the more specific

goals

5.2 Situational and F

unctional A

nalysis


Figure 9.8 STAR Table for Decision Support (adapted from Zachary, 1988)

Decision situation: (Name of decision situation) Task dynamics:

(state types – closed loop, iterative, unfolding, or single instance) Situational objective:

(highest level goal that the Decision Maker (DM) is trying to achieve) Value criteria:

(list of individual criteria by which alternative decisions are evaluated) Underlying process:

(a brief description of the observable process in which the decision situation is embedded) Information environment:

Inputs (list of available information items) Outputs (list of information items that are created) Parameters (list of information items that do not change value)

Intermediate reasoning / analysis steps: (list of intermediate reasoning steps or types of analysis that the DM typically applies in the

baseline process) Representation:

(a simple description including both the external world and the internal world) Judgment:

(required judgments, which are unstructured and intuitive activities)



Identifies the decision-making needs that arise from the constraints on unaided or the baseline decision-making process.

The general direction is; to refer to common limitations or biases in in decision making to examine what is relevant to the particular decision situation

as characterized in the prior stage of situational and functional analysis.

5.3 Constraint

Analysis



As stated earlier in Table 9.4 (Common Needs of Decision Making by Silver, 1991) in helping to overcome the limitations, Zachary (1988) too offers a similar list as shown in Table 9.5 (Common Limitations on Decision Making – Zachary, 1988) and relates them to the categories of the decision situation (Figure 9.8 - STAR Table for Decision Support – Zachary, 1988).

Tables 9.4 (Silver, 1991) and 9.5 (Zachary, 1988) are no more than checklists that need to be matched with the analysis documented in the STAR Table.

The product of this stage is a list of specific decision-making difficulties.

5.3 Constraint

Analysis


Table 9.5 Common Limitations on Decision Making (Zachary, 1988)

Inability to predict processes It is difficult to project processes due to limitations on working memory, attention to detail,

and numeric processing. Possible outcomes are projecting with errors, relying on suboptimal techniques, and ignoring information.

Difficult in combining attributes and objectives that are competing It is difficult to combine ill-defined objectives or conflicting objectives, due to limitations on

working memory and numeric processing. Possible outcomes are incorrect integrated criteria and omission of important attributes or objectives.

Inability to manage information Due to limitations on working memory and long-term memory and also limited attention.

Possible outcomes are errors in using the information and ignoring information intentionally and unintentionally.

Difficult in analyzing and reasoning Limitations on knowledge, time, and effort make it difficult to formulate an effective

decision strategy or to carry it out correctly. Difficulties in visualizing

It is difficult to visualize abstract manipulations and semantic data. It is easier to visualize concrete situations but difficult to manipulate them, due to limitations on working memory and cognitive processing. A major outcome is limiting the ability to manipulate information and therefore producing less effective solutions.


SUMMARY

Positions HCI within the organizational context by addressing task and work.

Differentiate between task at the organizational level and task at the tool level and position both on one task hierarchy, where tool-level tasks are the means for accomplishing the higher organizational-level task.

Looks at the characteristics of organizational tasks and work to help define user requirements by identifying needs or difficulties.

Eventually looks at methods for analyzing and decomposing tasks.

This

Chapter;


SUMMARY

WORK is the ensemble of interrelated TASKS and WORKERS who perform the task.

The general characteristics of a TASK, particularly the task’s degree of structure, determine the types of computer support that are most appropriate in order to boost performance, ease work, and generally satisfy the user.

The general characteristics of WORK, particularly the types of users and the interrelations between tasks performed by the same person or groups of workers, also dictate the limitations users face and the computer support they require.

The analysis of tasks in the work context they are performed is the basis for determining user requirements and designing HCI.

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